“Click” type floor coverings comprise a plurality of substrates, each provided with like joint systems to facilitate coupling of adjacent substrates. These joint systems often comprise first and second joints running along two opposite sides of the substrate. The joints are configured so that the first joint on one substrate is able to engage the second joint on an adjacent substrate. The joints rely on specific configurations of tongues, grooves, protrusions, recesses and barbs to effect interlocking engagement.
Joint systems for flooring may be generally categorised as horizontal joint systems, lay down joint systems or vertical joint systems. Horizontal joint systems require motion in a plane substantially parallel to a plane containing a major surface of the flooring substrate (i.e. a horizontal plane) in order to effect the engagement of joints on adjacent substrates. In lay down systems panel are joined by inclining one panel to insert a tongue into a groove of a previously laid panel then laying down or pivoting the inclined panel to be co-planar with the previously laid panel. Vertical joint systems on the other hand require motion and/or force in a plane perpendicular to a major surface of the substrates to effect engagement of the joints. Thus it should be understood that the expression “vertical” in the context of the present type of joint system, and as used in this specification, does not mean absolutely vertical but rather perpendicular to a major surface of a substrate. When the substrate is laid on a horizontal surface then “vertical” in this context is also absolute vertical. But as those skilled in the art will understand substrates can be laid on surfaces of other dispositions for example on vertical surfaces such as a vertical wall; or, inclined surfaces such as on a pitched ceiling. In such situations the vertical joint system holds it's meaning as a joint system that operates/engages by way of motion and/or force in a plane perpendicular to a major surface of the substrates
Horizontal and lay down system are generally characterised by mutually engageable tongues and grooves. In this context, the term “tongue” is understood as meaning ‘a protrusion extending distally from a side of a panel spaced inwardly from the top and bottom surfaces of the panel’. This definition was provided by the Honourable Rudolph T. Randa, Chief Judge in the Markman Claim Construction decision in Order nos. 02-C-1266, 03-C-342, 04-C-121-Mar. 6, 2007 in relation to U.S. Pat. Nos. 6,006,486 and 6,490,836 assigned to Unilin Beheer B. V. Indeed in the Markman hearing Unilin themselves proposed the term “tongue” be construed as “a protrusion extending distally form a side spaced inwardly form the top and bottom surfaces and including at least one locking element”. Similarly in US International Trade Commission Investigation no. 337-TA-545 it was held that ‘tongue’ means ‘a coupling part extending from the edge of a board, where the coupling part provides primary coupling in the horizontal direction and primary locking the vertical direction’ and ‘groove’ means ‘a coupling part that cooperates with the tongue to connection two panels together’.
The above references to the background art do not constitute an admission that the art forms a part of the common general knowledge of a person of ordinary skill in the art. The above references are also not intended to limit the application of the joint system as disclosed herein.